Dental flask



Aug. 31, 1943. V s. E. MacDOUGALF DENTAL FLA-SK Filed Sept. 9, 1941 ATT P organ?? v Patented Aug. 31, 1943 UNITED STATES PATENT OFFICE.

i ,g Y 2,328,285. a a

1 .DENTAL FLASK V Seymour E.Mac l)ougall, Bufia lo, N. Y. Application s ptemter 9, 1941, Serial No. 410,157

. t 7 Claims. invention relates to a dental flask and more particularly to such a dental flask for molding and vulcanizing artificial dentures.

One of the principal objects of the invention is to obtain an absolutely true and accurate reproduction, inrubber or other plastic, of th wax model of the denture. i t

Another object of the invention is'to provide such a dental flask which can be readily and gently opened-without danger. of injury to the teeth or plate of the artificial denture, especially the danger 'of breaking anterior teeth with long bites, or fragile plates.

Another objectis to provide such a flaskvvhich will save the time of the operator in removing the plaster investment.

Another purpose is to provide such a flask whichwill accommodate allthelarge and varied sizes of artificial dentures and in which all of Fig. 1 is a front elevation of arms]:

the different plastic materials employed in den my invention.

Fig; 4 is a horizontal section, taken on line Figs. 5 and6 are vertical sections, taken onthe correspondingly respectively." v H o Fig.3? is a fragmentary, vertical section, taken online1,-|,Fig. 4l o Fig. 8 is a frgmentary section, taken on line In gerieral the flask is shown as comprising a multipart flask comprisinga bottom portion, an

intermediate portion and a top oricover portion,

W lines n F gs. 2 an 1 i bottompo r tion and the top or cover portionbe ing provided with lugsj on the underside of its margin which interfit with other centering recesses in the rim of the intermediate portion. The flask portions are adaptedto. be filled with plaster of Paris, or other solidifying plastic and the wax model with the teeth in position is placed in the plaster of Paris, suitable provision being made to permit of parting of the plaster investment. After the plaster of Paris has set, the wax is boiled out and rubber or other plastic is substituted for the wax and the flask placed ina vulcanizer to vulcanize the rubber. The plaster investment is then removed from the flask and the completed denture removed from the plaster.

The dentaljflaskforming, the subject of my invention as shown in the drawing, comprises a bottom portion I0 of cup-like form having, in

plan, a horizontally straightback wall. II and a rounding front wall I 2. The inner faces of these walls are preferably vertical, as best shown in Figs. 5 and 6, This bottom portion is made of two sections la and 10b, the rear wall of the section, I Do being made to provide a pair of hinge eyes it! at its inner edge and the rear wall of the section lllb being formed to provide a single hinge eye M which fits between the hinge eyes I3. A

vertical pintle I5 connects the hinge eye I3 and Msojthatfthetwo parts of'the bottom portion I 0 are opened by separating the frontends of the sections, the location ofthe hinge connection in the rear walls of these sections facilitating the freeing of the sections from the plaster invest-f ment since the location of this hinge connection, for example, in the front wall of the bottom portion would render it impossible to separate the two section without breakin the plaster core. To further facilitate the'separation of the two halves of the lower portion 10, a vertical screw. driver slot It can be'provided in thellowerfront corner of the bottom portion l0 between the two sections Ilia and lilb and into which a screw driver can be inserted to force the two sections apart, if necessary. v o

To prevent the leakage of fluid plaster from between the two sections Illa and lflbof the bottom portion of the flask, the bottom of the sectionlll'a is recessed on itsunderside and along its inner edge adjacent the hinge connection to tion to form anupward continuation thereof being provided with Iexternalyertical recesses which receive upright "centering fingers of the provide atongue ll which'fits into a correspondingggroove provided in the other section lob. This tongue ll extends to the center of the lower portion Ill of the flask at which point the relationt of th etongues and grooves of the two sections is reversed, the section 19a being recessed in the upper side of its bottom along its inner edge to receive a corresponding tongue l8 provided in'the section lflb. This tongue l8 extends to the front Wall of the section [b which front wall is recessed in its outer front corner to receive a vertical tongue [9 in the front wall of the section 3a..

The two halves of the bottom portion H] of the flask are drawn together, and locked in a closed condition by a latch on the front wall, this latch being indicatedfgenerally at 28'. Eon-this latch,

- the frontwalrofthesection Nib its-provided with a boss 2| and the front wall of the section la is provided with a boss 22, the front faces of these bosses being fiat to provide a coplanar verticalfaot at the front of the flask. A screw 23 projects horizontally forward from the boss .35] and aesorewfifli projects horizontally forward from. the boss: 22..

The latch includes a fingerpiec'e 25'wliich is" of'thislatch member 28"is formedtocprovide a I hook 28fwhichlis shaped';to. catch; the screw 2d. It will'flthereforebeseen. that after the sections Ina. andlllib offthebottQm portionofthehfiask are closed; therhock. 219' can .be swungover, the screw 2.4"and; the. fingerpiece..25"rotatied so that its e0.- centrically monntedlhub is caused; to draw. the latch-members 218Ltolthe right, 'as viewed"in .Figs. llandLS; and; thereby. draws, the sections ma and] rib: tightlytogether.

Each off these. sections I 011 and; I01), is provided withanupstanding centering, finger, 30.," these ,fingers qroiiectiii g up. fromthe rims of these seem tions. atlthe outer sides of the rims. These ets. are. preferably. provide ,withans abrupt .vere

tioal; front. corner. 31 and; a... tapering; rear, edge 7 32 and; are receivedjin correspondinglyshaped recesses isfii'provid'ediin anintermediateflasklportion 35. This. ,intermedihtehdrtibn; or. the flask isra singlecasting in the form.,. of,an.open rim whichis formed; to rest on ,and provide an .up;

Ward; continuation .1 oi; the .rims of..." the; sections andjth'e centeringfingers .3lj.ihsnre .theeaccn-rate resister.. oii;thiscintermediateisections Ituwi-llybe. seen. that...the. shape. of.jthese-.,centering fingers-35 and theirqrecesses. permit the, two" sections I'Oh andl iibiiofithe bottom portion. .of JtheflasKtobe openediand' 'closed'wlfiile in en a ement" with. the. mtermedi'ateportion 3.67.... Theihner. face of; the. intermediate porti'onfi'zlreS. outwardly. toward Ith'e bottom of.theintermediateportionso as to if'acili tate l its ready vertical-immoral lfrionr the plaster investmentuandl this, innerqfacewforms a smooth continuation of'th'e inner facepofjtheside walls H and I2 ofthebottom flask; pprtionwlfii.

To facilitate. the separation of'ftlle .PQlti'onsJ andij 38 Set; the flask, the back. wall jJ'l ofitth'el bot-3 tom portion is preferably; provided at its,v upper. edge withscrew driver slfots 38.into whicnascrew. driver can be inserted for prying the fiask'portio 's apart'to release theplaster investment.

The intermediate fiaskf-nortion 3b is provided; in its upper part: with a" pilntaiity of*'spaced%re= cesses 40* which are-formedto' fit centering" lugs,

(iii

or cover plate 42 of the flask. Thiscover is of generally flat form and is provided with vent openings 43. This cover may also be provided with a horizontally extending lip 44 at one side which may be tapped to free it from the intermediate fiask portion 36 and the plaster investment being released.

In order to prevent the latch from accidentally loosening after it has been closed, the fingerpiece is shown as provided at its upper edge with a-Jnotch. 45- which, in the closed v position of the latch, embraces a lockingscrew' 46. After the latch 20 has been closed, the locking screw 48 is tightened down so as to hold the parts of the-latch in the closed position until this locking screw is loosened.

' From. the: foregoing it will be seen that the present invention provides a dental flask which is ofsimple and'strong construction and which is readily assembled and filled with the necessary materials for producing artificialldentures and can be" readiliyiopened to-release the plasterinvestment' witliout'danger" of breaking-or distort:- ing the denture; V

Icl'aim as my invention :1

1-3 A, dental" flask ofgthe character described, comprising a cup-shaped bottomiporti'on having a. bottom Wall and a rim, an intermediate portion interfitting with" the rim; of said "bottom portion and a" cover fitting over 'sai'd'zintermed'late. portion and enclosing, flask; said" bottom: portion being mad'e' of two side sectionsfitted t0.- gether along a central substantially" straight parting. line extending throughsaidibottom Wall andth'e opposite sides offsaidirim; ahinge having a Verticalpintle connectingsaidsections at oneside of said .fiask and a latcli'lconnecting said sections at the othenside offsaidfiaskt.

2';.A dental flask of the characterl described, comprisihga Cup-shaped. bottom ,portion-having a bottom wall and a rim forming; in .p,lan,.a. hori.- zontally, straight reanwall and rounding; side. and end. Walls. connecting the 7 ends of said. straight rear wall, an intermediate.portionlinlthecform of a, rimlinterfitting with said'irimiofe saidbottom portion, aL cover. fitting, over. sa-idl intermediate portion-andjenclosing,saidifiaslelsaidlbottomlpors than being made of'tWo side sectionsifittedetos gether along a partingdinesextending centrally through .saidstr'aight .rearWwalLlsaid bottom wall andsaid" rounding front wall; an external. hinge having a vertical pintle. connecting said sections at said straight rear walllzandlaclatchiconnecting said sections at the. frontsid'ei. oti'the ,flask;v

32 A' dental flask of the characten described; comprisinggla cup shaped bottom. portion, airintermediat'a portion in the f ormiof .a ,riinandtim. t'erfittingwith the rim of said bottomportiom anda coven fittedoyer saidlintermediateportion and enclosing said flask, said bottom .-p ortio-n::be.-, ing. madeofltwo.sections. formed o-n theiriopposihg edges with interfitting tongues and-grooves; a. hingehailing a. vertical pintleconnecting said sections-.at...one. side of..'the :flaskand .a-i-latch: 0011- nectingrthesectionsatithe other side of thefiask.v

4L1; dental, fiaskioflthe; character. described comprising, aacupi-shapedi bottomportion having, a..riin .witiia. verticaliinner face, anintermediate. pontionin thelform ofbaronezpiecei rim, theinnen f'acaofiwhidh formsv acohtihuatiom of .Isaid ver. tioal'innerlface of saidrini ofsaidbottom portion. andH-tap ers inwardly from..its'. line,..of juncture. withAsaidverticali'inner face ofijsai'd rimtofl. said; b'o'ttomportion to .a smallerropjening. inthe top,

-41*provided on-the undersideoffith-e'top portion 75. oftsaidintermzediate portion; and a coverfitting,

over said intermediate portion and enclosing the flask, said bottom portion being made of two sections fitted together, a hinge having a vertical pintle connecting said sections at one side of said flask and a latch connecting said sections at the other side of said flask.

5. A dental flask of the character described, comprising a cup-shaped bottom portion, an intermediate portion in the form of a one piece rim arranged on the rim of said bottom portion and forming an upwardcontinuation thereof, a

cover fitting over said intermediate portion and enclosing the flask said bottom portion being made of two sectionsfltted together, a hinge having a vertical pintie connecting said sections at one side of said flask and a latch connecting said sections at the other side of said flask, the

rim or said bottom portion being formed to pro vide upwardly projecting centering fingers and said intermediate portion being externally formed to provide recesses receiving said fingers.

6. A dental flask of the character described.

comprising a cup-shaped bottom portion, an intermediate portion in the form of a one piece rim arranged on therim of said bottom portion and forming an upward continuation thereof, a cover fitting over said intermediate portion and enclosing the flask said bottom portion being made of two sections fitted together, a hinge having a vertical pintie connecting said sections at one side of said flask and a latch connecting said sections at the other side of said flask, the,

rim of said bottom portion being formed to provide upwardly projecting centering fingers and said intermediate portion being externally formed to provide recesses receiving said fingers, said fingers and recesses being formed to permit said bottom portions to be opened and closed while engaged with said intermediate portion. a

7. A dental flask of the character described, comprising a cup-shaped bottom portion, an intermediate portion in the form of a one piece rim arranged on the rim of said bottom portion and forming an upward continuation thereof, a

cover fitting over said intermediate portion and enclosing the flask said bottom portion being made of two sections fitted together, a hinge having a vertical pintie connecting said sections at one side of said flask and a latch connecting said sections at the other side of said flask, the rim of said bottom portion being formed to provide upwardly projecting centering fingers and said intermediate portion being externally formed to provide recesses receiving said fingers, said intermediate portion and cover being provided with interflt'ting lugs and recesses to centerthe same with reference to each other.

SEYMOUR E. MACDOUGALL. 

